Einstein's Errors—Part 2

So Einstein is still king of physics... his ideas remain true. Yet many an experimental physicist over this last century has planned a test with the secret desire of showing Albert to be wrong in one of his basic ideas. One reason is that scientists always try to show a theory is wrong... and if they fail, it gives them more confidence that the theory is right. But also, if an experimenter could demonstrate a major flaw in one of Einstein's theories, wouldn't that gain him everlasting fame? If E = mc² was not correct, wouldn't that knock the socks off the scientific world? If something was discovered to move faster than the speed of light, how might that rattle the foundations of science?

In fact, four years ago worldwide headlines frenetically trumpeted that an experimental research team in Europe had announced that their measurements indicated that neutrinos traveled faster than the speed of light. That news set off a string of wild speculations in the public mind. Einstein—the god of physics—wrong? The absolute upper speed limit of the universe broken? It was almost as dramatic as demonstrating that the sun does revolve around the Earth. Many people chuckled knowingly, contending that they hadn't believed in Albert's speed limit anyway.

Most scientists were quoted as being convinced that something in the neutrino experiment had to be flawed—the whole foundation of physics rested on the fact that nothing moved faster than light. Even the team of researchers who ran the experiment doubted their result, but their measurements had repeatedly found the same thing. In fact, their announcement was partly intended to get the world's physicists to examine their work and find a flaw. A flurry of activity occurred over the following year and suggested modifications were tried. The measurement error was found, soliciting a collective scientific sigh of relief that the speed of light had prevailed.

I find it interesting that the popular press has been far more subdued in announcing that Einstein was right, than when they snickered about his error. It's similar to someone tweeting some fantastic phony claim (“Obama is a Muslim!”) that goes viral, spreading instantly across the globe's viewing screens. Careful fact checking soon disproves the false assertion, but the damage has been done. The correction never gets the equal notoriety that the first phony claim did. (Day one headline: “Obama was not born in America!” Day two correction in tiny print on page 17: “Yes he was.”)

I think, that here on the 100^th anniversary of Einsteins' general theory of relativity, there is more to a scientist's motivation for trying to disprove his ideas than wanting to go down in history as the guy who out-thought the great man. There is a propensity for people to make someone like Einstein a hero or create a god-like vision of him. The public image grows over the years, as the vision expands. But other people dream of knocking the hero down from the pedestal, to show that he's a fake after all.

I'm not sure what all motivates some people to want to see that Einstein was wrong. The case of the faster-than-light neutrino was a recent spectacular example. I take comfort from the fact that Albert broke the physics mold over a century ago and that his insights are still very much intact. You rock, Albert!

Einstein as a Halloween Pumpkin Carving

Einstein's Errors—Part 1

One hundred years ago the world was notified by an obscure patent-office clerk in Switzerland (one Albert Einstein), that its notion of how gravity worked was wrong. For more than 200 years before that, Newton's description of the “universal law of gravitation” had been considered irrefutable: gravity was a force that can be expressed as an attraction between two or more bodies. Thus, if I hold out a ball, the Earth attracts the ball toward it through a gravitational force, and when I release the ball, gravity pulls it straight down.

Einstein rewrote our concept of the physics of gravitation when he published his general theory of relativity in December 1915, titled “The Field Equations of Gravitation.” Instead of the Earth pulling a ball downward, the mass of the planet literally bends or warps space around it. Then, as the ball travels, it's forced to follow the warped space field, right into the planet. The image is a little easier to grasp if we ponder the Sun, whose huge mass warps space so much around itself that Earth, “thinking” it's following a straight line, actually circles the sun. The “straight lines” of space have literally been curved by the sun's huge mass.

Not many scientists—let alone average people—in 1915 bothered to heed the scribblings of a lowly German patent clerk in Switzerland. But four years later a prominent English astronomer used Einstein's equations to explain an anomalous shift in the apparent position of a distant star as its image passed behind our sun during an eclipse. Overnight Einstein became a science rock star. For the next 40 years Albert remained in the physics limelight, as he continued his researches. He remained in the public limelight also; abetted by his fascinating personal idiosyncrasies, wild hairdo, and otherwise photogenic appearance.

Few scientific figures have ever approached Einstein's fame. (Maybe today, Steven Hawking is close.) His discoveries came from his unique ability to blend a keen skill at mathematics, with a penetrating insight into experimental measurements, but topped off by his talent at conducting thought experiments. His thought experiments were a crucial ingredient in his work, because most of what he studied could not at the time be tested by physical experiments. Humans had yet to visit space or build the required complicated test equipment to run the necessary experiments. These came later, when they subsequently verified every abstract equation and thought experiment that he had run inside his head.

Over the last 100 years Einstein's theories have repeatedly shown to be correct. Not one significant error has been found. He was not perfect, and physicists love to mention his small errors, but they have never denied his fundamental insights. The man has been right on.

More on Einstein's errors next time...

My Owl--by Night and by Day

Our Best Friends

Numerous scientific studies have unequivocally shown that dogs—considered by many people to be “man's best friend”—descended from the wolves. This result comes from DNA studies of wolves and dogs. The estimated date of when dogs became our buddies is as yet a little hazy: anywhere from about 13 thousand years ago to as long ago as 30 thousand years. The relationship between wolves and dogs is also demonstrated in their scientific names: Canis lupus (for wolves) and Canis lupus familairis (for dogs). We certainly are more familiar with dogs.

A tougher question about the evolution of wolves to dogs is: How did the first dogs transform from wolves? By what process did those pioneer wolves come in from the wild and buddy-up to our ancestors? The answer to questions like these cannot be investigated by DNA experiments in the laboratory, nor are there any historical documents waiting to be discovered (since no human was able to write at the time). Nonetheless, recent research is offering some insights to understand how dogs evolved from wolves.

A common belief for many years has been that dogs evolved when an enterprising hunter-gatherer encountered some cute wolf puppies and carried a couple of them home to the cave to adopt. In time the little wolves became tame and the rest of the story is history. That tale has been debunked. The lifestyle of our hunter-gatherer ancestors was too nomadic to allow them to carry out such a lengthy process. In addition, modern studies of wolves have shown that, although wolves can be socialized and even tamed, they retain a large degree of wildness, that keeps them from connecting with people as deeply as dogs do. Finally, what sane hunger-gatherer parent would allow a wild wolf to get cozy with their kids?

Research has shown instead that humans did not domesticate wolves... wolves did it themselves. Dogs are thus self-domesticated wolves. They chose us. Why? How? Very recent studies have shown that dogs are a rare type of critter who possess a kind of intelligence that allows them to interpret our intentions. They read our behavior and body language and perceive what we literally are thinking. In humans this ability is called “theory of mind.” Here's how it works: I know that I have a mind, I assume that other people do, and further, I assume that how I respond to things is similar to how other people do.

Dogs do not have this level of cognitive ability, but they do have a remarkable ability to read our intentions. It is a capability that allowed them to domesticate themselves and learn to live with us, long ago. They were clever enough to perceive that life would be much easier if they became our buddies. We would be their source of food (our leftover garbage) and rather than compete with us in hunting down animals (as have their wolf cousins), they could partner with us and benefit from our skills (and vice versa).

As an example, the dog is unique among animals in understanding that when we point at something, we are drawing their attention to it. Wolves can't do it. Even our closest relatives, the chimpanzees and bonobos, can't do it. This ability allows dogs to make inferences about our intentions and to flexibly and creatively solve new problems for themselves—things that neither wolves nor apes can do.

So we humans have more in common with dogs than we've previously thought. When we evolved from apes into Homo sapiens, we later developed the theory of mind, which has allowed us to develop a unique form of communication and to cooperate to achieve impressive things. When dogs evolved from wolves (on their own initiative) they developed a similar ability, that gives us and them a unique form of communication and cooperation. Does that not make them our best friends?